IB/mlx5: Verify DEVX general object type correctly

As the obj_id in the firmware is not globally unique in general_object,
the object type must be considered upon checking for a valid object id.

Fixes: 2351776e ("IB/mlx5: Verify DEVX object type")
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>